Taste is the paramount sense governing which foods are accepted or rejected. It is the final arbiter of what goes into the stomach and what is rejected. We believe this is because the taste of food is, in general, the most important marker of its identity and acceptability. To this point, chemosensory clinical patients who present with taste complaints are twice as likely to report weight loss as those who present with olfactory dysfunction (40% vs. 20%) and enjoy food less. We, therefore, wish to understand the loss and recovery of chemosensory taste function in patients who have iatrogenic taste nerve damage during middle ear surgery. The chorda tympani (CT) nerve, which innervates the taste buds of the anterior two-thirds of the tongue, may be damaged during this surgery. As a clinical problem, the physician is unable to predict for their patient the degree or chemospecificity of their potential taste loss or precisely when normal function will return. From a basic research perspective, the proposed work will investigate the potential for a human cranial nerve and receptor end organs to re-grow and regenerate. A better understanding of a fully regenerating organ and tissue has great potential to help us understand how other human tissues, which do not spontaneously regenerate, may be induced to do so. The Aims of this proposal are to explore the loss and recovery of taste perception as a function of the type of CT nerve damage that occurs during surgery and the concomitant changes to human taste buds. PUBLIC HEALTH RELEVANCE: Taste is the final arbiter of what is eaten and what is rejected. Patients who present with taste complaints may lose interest in food and body weight. We wish to understand the loss and recovery of taste function in patients who have taste nerve damage during surgery of the middle ear. We will explore the loss and recovery of taste that occurs during surgery and the concomitant changes to human taste buds.